Blog Feed / Front Page Sidebar (Pro only)
You can choose to show or hide a sidebar on the blog feed. Go to Appearance > Customizer > Blog Feed and toggle the Show Sidebar on Blog Feed option.
By default, the blog feed shows with a sidebar on the right. If you choose to hide the sidebar, the Post Display Format setting will be ignored and the posts will be shown 3 in a row.
Click here for a demo of a full width front page.